缺血预处理和长托宁防治脊髓缺血再灌注损伤的实验研究

Preventive effects of ischemic preconditioning and penehyclidine hydrochloride on spinal cord against ischemia-reperfusion injury in rabbits

目的探讨缺血预处理和长托宁对脊髓缺血再灌注损伤的防治作用及其可能的作用机制。方法家兔24只按随机数字表法分为假手术组（A组）、缺血再灌注组（B组）及缺血预处理（TPC）和长托宁治疗组（C组）。B、C组阻断腹主动脉40min，再灌注7d。C组IPC 5min，再灌注30min，再灌注20min时静注长托宁0．2mg／kg。分别测定阻断前10min（C-10）、开放前即N（C40）、再灌注60min（R50）及7d（R7d）血清丙二醛（MDA）、超氧化物歧化酶（SOD）、肌酸激酶（CK）、肌酸激酶脑型同工酶（CK-BB）；观察术后后肢神经功能；镜下脊髓病理学观察；计数脊髓凋亡神经元。结果缺血再灌注后B组MDA、CK、CK-BB值明显高于C-10及A组相应时点值（P〈0．05或P〈0．01），SOD值变化同MDA变化相反；C组MDA、CK、CK-BB值明显高于C-10值（P〈0．05），但明显低于B组相对应时点值（P〈0．01），差异有统计学意义，但较A组差异无统计学意义。B组凋亡细胞数明显多于A组；C组明显少于B组，但多于A组，差异有统计学意义（P均〈0．01）。C组瘫痪发生率明显低于B组，其后肢神经功能明显好于B组，差异有统计学意义（P均〈0．01）。C组脊髓病理变化明显轻于B组。结论IPC和长托宁对脊髓缺血再灌注损伤有良好的防治作用，其机制可能与其抗氧化反应及防治脊髓细胞损伤作用有关。

Objective To investigate the protective effect of ischemic preconditioning （IPC） and penehyclidine hydrochloride （PHC） on the spinal cord against ischemia-reperfusion injury induced by aortic cross-clamping in rabbits. Methods Twenty-four rabbits were randomly divided into sham operation group （A）, ischemia-reperfusion injury group （B） and IPC＋PHC group （C）. In group C, IPC was performed for 5 min, followed by reperfusion for 30 min, and PHC （0.2 mg/kg） was given at 20 min of reperfusion. Then, in group B and C, the infrarenal aorta was clamped for 40 min followed by 7 d reperfusion. The aorta was not clamped in group A. The plasma concentrations of malondialdehede （MDA）, superoxide dismutase （SOD）, creatine kinase （CK） and creatine kinase BB isoenzyme （CK-BB） were assayed at 10 min before clamping, before unclamping, at 60 min and on the 7 th day after unclamping. After an operation, the neurological outcomes of the hind limbs were evaluated, the morphology of the spinal cord was observed, and the apoptotic spinal cord cells were measured by immunohistochemical technique. Results The concentrations of MDA, CK and CK-BB after ischemia-reperfusion in group B were increased significantly compared with those before clamping and those in group A （P〈0.05 or 0.01）; the concentrations in group C were higher than those before clamping （P〈0.05）, but lower significantly than those in group B （P〈0.01）, and not significantly different from those in group A. SOD was opposite. The apoptotic cells in group B were much more than that in group A and in group C, but the number in group C was significantly higher than that in group A （P〈0.01）. The incidence rate of paralysis in group C was significantly lower than that in group B, and the neurological score of hinder limb was higher in group C than in group B （P〈0.01）. Pathological changes of the spinal cord was milder in group C than in group B. Conclusion The combination of IPC and PHC can protect the spinal cord from ischemia-reperfusion injury in rabbits; the main mechanism may be increasing antioxidant potential and preventing cell injury.